The present invention relates to a process for producing heat-sensitive recording materials which provide developed images by the reaction between a color former and a color developer upon heating.
Conventional heat-sensitive recording materials, widely used in facsimiles, various printers, or electrocardiographs, for example, exhibit an undesirable lack of stability in high humidity conditions. If these recording materials are subjected to high humidity conditions after recording, the density of recorded images decreases and finally fades to such an extent that the images can no longer be read. Further, if the recorded images are rubbed with fingers or with a cloth after contact with moisture, they readily disappear.